Measurements of plasma parameters in a hollow electrode AC glow discharge in helium

Measurements of the plasma parameters of coaxial gridded hollow electrode alternating current (AC) discharge helium plasma were carried out using an improved probe diagnostic technology. The measurements were performed under well-defined discharge conditions (chamber geometry, input power, AC power frequency, and external electrical characteristics). The problems encountered in describing the characteristics of AC discharge in many probe diagnostic methods were addressed by using an improved probe diagnostics design. This design can also be applied to the measurement of plasma parameters in many kinds of plasma sources in which the probe potential fluctuates with the discharge current. Several parameters of the hollow electrode AC helium discharge plasma were measured, including the plasma density, electron temperature, plasma density profiles, and changes in plasma density at different input power values and helium pressures. The characteristics of the coaxial gridded hollow electrode plasma determined by the experiments are suitable for comparison with plasma simulations, and for use in many applications of hollow cathode plasma.